Differential signaling is a method for electrically transmitting information using two complementary signals. The technique sends the same electrical signal as a differential pair of signals, each in its own conductor. The pair of conductors can be wires (typically twisted together) or traces on a circuit board. The receiving circuit responds to the electrical difference between the two signals, rather than the difference between a single wire and ground. The opposite technique is called single-ended signaling. Differential pairs are usually found on printed circuit boards, in twisted-pair and ribbon cables, and in connectors. The electronics industry, particularly in portable and mobile devices, continually strives to lower supply voltage to save power and reduce emitted electromagnetic radiation. A low supply voltage, however, reduces noise immunity. Differential signaling helps to reduce these problems because, for a given supply voltage, it provides twice the noise immunity of a single-ended system.
Routing high-speed (>1.0 Gbps), high density differential signals out of small pitch (distance from pin to pin), BGA (Ball Grid Array) from an SoC (System On a Chip) to a traditional linear single or multi-row connector is extremely difficult to achieve while maintaining positive transmission line effects. Some of the things that help maintain positive transmission line effects are short trace lengths that must be distance and phase matched, to achieve signal symmetry. Differential routing for multi-lane interfaces dictates that all trace lengths must match the longest signal trace. Not only does a differential pair match, but all lane pairs that are part of the defined interface. Reach is the maximum distance that a signal can safely travel through a particular medium without degradation. Due to challenging layout trade-offs, this may force a conflict with a design specification's reach requirements. Traditional rectangular multi-signal linear connectors take so much space that they block other routing that needs to be routed out of the SoC's BGA field. Traditional linear connectors tend to create longer trace lengths, or push-out from the BGA field due to right angle triangle hypotenuse to base length differences. Consider right triangle geometry: The base of the right triangle is the shortest distance from pin (or ball from a BGA) to the traditional linear connector—distance “b” in FIG. 1. The hypotenuse is the longest distance from the SoC to connector end connections of the connector—distance “c” in FIG. 1. The longest distance always determines the minimum differential routing. Shorter base distances create huge problems for routing due to the need for aggressive trace elongation to match the hypotenuse trace length. This trace elongation in confined space appears in two forms: serpentine and trombone trace type configurations as shown in FIG. 2. Serpentine trace configurations look like a, “snake in the sand”, while the trombone traces look similar to the bends in the musical instrument from the mouthpiece to the bell, which have two long 180 degree bends. This exacerbates the problem of routing other signals out. Thus, the connector is “pushed-out” farther away from the BGA field as a trade-off in support of routing other signals as well as meeting matched length requirements of differential signals.
A new connector type needs to be implemented to overcome the significant challenges of routing many high channel count HSIO's (High-Speed Input/Output) out of a SoC's package. These could also be used in small geometric areas without degrading the HSIO signals, while allowing other signals to be safely routed out. Accordingly, there is a need for systems, apparatus, and methods that overcome the deficiencies of conventional approaches including the methods, system and apparatus provided hereby.